Process for producing a textile fabric



Patented May 26, 1953 PnooEss FOR PRODUCING A TEXTILE FABRIC WilliamEwart Stanley and Fred Carter Brown, Spondon, near Derby, England,assignors to British Celanese Limited, a corporation of Great Britain NoDrawing. Application August 30, 1950, Serial No.'182,428. In GreatBritain September 15,

7 Claims.

1 This invention relates to knitted fabrics and especially to knittedfabrics having a patterned appearance.

We have found that by knitting a fabric from both yarns of celluloseacetate filaments and yarns of artificial filaments of linear polymers.which have been oriented as by cold drawing,

fabrics can be obtained which undergo a change in appearance upon beingsubjected to a hot aqueous treatment and that valuable patterned fabricscan thus be obtained.

The present invention comprise a knitted fabric in which the yarnsknitted together comprise alternate groups of yarns of cellulose acetatefilaments and yarns of filaments of synthetic linear polymers which havebeen oriented as by cold drawing.

The commercial yarn of filaments of the nylon obtainable by condensinghexamethylenediamine with adip-ic acid (nylon 66) which yarns haveundergone cold drawing, for example to the extent of several hundredpercent of their length as spun, is an example of such a cold drawnproduct. The invention will be more particularly described withreference to the use of this type of oriented product.

Thus, a plain warp knitted fabric may be knitted up from alternategroups of celluloseacetate yarns and nylon 66 yarns, that is a two barfabric of which the yarns of each bar consist of alternate groups ofcellulose acetate yarns and nylon 66 yarns and the nylon yarns of thetwo bars are in corresponding positions in the fabric. These groups mayconsist alternately of say 9' threads of the nylon yarn e. g. yarn ofabout 45 denier) and of 18 threads of cellulose acetate yarn (e. g.

of about 55 denier). Again, the groups may consist alternately of agroup of 18 threads of the nylon yarn and a group of 10 therads of thecellulose acetate yarn. Upon scouring the knitted fabric with or withoutdyeing, for example, at a temperature of 70-80" C. and thereafterfinishing in th manner usual for cellulose acetate warp knitted fabrics,a product of marked ribbed character is obtained in spite of the factthat all the constituent yarns have been knitted into the fabric in thesame manner. The nylon 66 portions of the fabric form ribs which standup on the face of the fabric in the direction of the .lengthof thefabric, that is, at right angles to the knitting courses.

The effect appears to be due, in part at least, to the nylon yarnundergoing more shrinkage during the hot aqueous treatment than thecellulose acetate yarn. The effect thus obtained is remarkablypermanent, resisting for example many launderings without substantialchange in appearance. r

The fabric may be a lock-knit fabric,-i. e .-a two bar warp-knit fabricin which each yarn of the back bar moves from wale to wale between suc-Alternatively, the yarns of one or both bars may move between coursesover a greater distance than in the case of a lock-knit fabric. Againthe fabric may be a three bar or more complex warp knit fabric. 7

Further, the cellulose acetate yarns and the nylon yarns may be insmaller groups than those indicated above. 7 For example groups of 2 to4 yarns may alternate (on each bar). In general the most attractiveeffects are obtained in the case of a two bar fabric when the groups ofone kind of yarn on each bar contain not more than 30 yarns, forinstance not more than 20 yarns. The fabrics of the invention may be oftypes of knit other than warp knit. For example they may be circularknit fabrics or fiat knit (i. e. weft knit fabrics). In the case ofplain circular knit fabrics the effect of the alternating groups ofyarns is to give a rib in the direction of the yarns in the fabric, 1.e. parallel with the knitting courses. Such fabrics may be produced oncircular knitting machines provided with yarn changing mechanism topermit of knitting the desired number of courses of one kind of yarn inalternation with the desired number of courses of the other kind ofyarn.

Particularly attractive fabrics are those of Warp, circular or flat knitin which the bands of fabric derived from one of the kinds of yarn eachcontain not more than yarns, for example not more than 40 yarns. Asalready indicated such fabrics are obtained in the case of two bar warpknitting by having groups of half the number of yarns on each bar.

If desired the knit, whether a warp orother knit, may be such as wouldgive a striped or other patterned effect, even if the fabric were contheknitted fabric can be used to modify profoundly the character of thefabric, especially when scoured and finished.

The effects produced by the simultaneous employment of the celluloseacetate yarns and the nylon yarns may be still further accentuated ormodified if the nyon yarns are under higher tension during knitting thanthe cellulos acetate yarns. This can be effected in the case of a warpknit fabric for example, by feeding the cellulose acetate yarns of eachbar from one beam and the nylon to the same bar from a second beamarranged to deliver its yarn at a higher tension than the beam ofcellulose acetate yarns. 'Im mediately after knitting the nylon yarnsretract still more relative to the cellulose acetate yarns than is thecase when the two kinds of yarn are knitted under equal tension and apatterned ef feet is obtained which can be substantially accentuated bysubjecting the knitted fabric to a hot aqueous treatment.

The hot aqueous treatment applied to the knitted fabrics in accordancewith the invention may be such as would normally be used in the scouringand dyeing of a cellulose acetate knitted fabric. Securing and dyeingmay, for example, be effected at a temperature of (iii-85 C. andparticularly at a temperature of 75-80" C. Soap or other detergents orwetting agents may be employed in the securing or dyeing baths. Theduration of the treatment may be conveniently of the order of an hour orsomewhat more. A shorter period is frequently sufficient to yield thedesired modification of the knitted material. Higher treatmenttempeiatures can, however, be employed, for example, temperatures up to100 C., particularly where delustring of the cellulose acetate is notobjectionable. Instead of using water in liquid form steam may beemployed whether at atmospheric pressure or at lower or higherpressures, for example, saturated steam at pressures of -30 lb. per sq.in. above atmospheric. It is desirable that the material should haveconsiderable freedom to shrink, at least in one direction, during thehot aqueous treatment.

The invention is further illustrated by the following example:

Example A plain lock-knit fabric is knitted up using for each of the twobars alternate groups of 9 nylon yarns of 45 denier and 18 celluloseacetate yarns of 55 denier. A second fabric is similarly prepared usingfor each bar alternate groups of 18 of the nylon yarns and 10 of thecellulose acetate yarns. The fabrics are sewn up into tubular form andloaded into a dye winch charged With cool water containing 2 grams perlitre of textile soap and 1 cc. per litre of Turkey red oil. The ratioof liquor to goods is about 20:1 by weight. The temperature of the bathis raised to 75 to 80 C. during half an hour and the fabrics processedat this temperature for 3 /2 hours. The temperature of the bath is thenlowered to below 40 C. by displacing part of the hot liquor with coldwater and the fabric unloaded, hydroextractcd and finished in the mannerusual for lock-knit fabrics.

Both fabrics exhibit a marked striped effect due to the nylon portionsstanding out from the face of the fabric.

If coloured fabrics are required suitable dispersed acetate rayon dyesmay be introduced into the processing liquor after half an hour at 75 5080 C.

The invention has been described more particularly with reference to theuse of cold drawn filaments of nylon 66 as the yarn to be knitted inwith the cellulose acetate yarn. In place of this yarn, yarn of orientedfilaments of other synthetic linear polymers (whether condensationpolymers or addition polymers) may be employed. For example yarn offilaments, oriented by drawing. of linear polymers of the followingkinds.

Polyamides other than nylon 66, particularly those from polymethylenediamines and polymethylene dicarboxylic acids.

Polyurethanes, e. g. those obtainable from polyalkylene glycols andpolyalkylene dis-isocya-nates or from polyalkylene diamines andchloroformic esters of polyalkylene glycols.

"Polyaminotriazoles described in U. S. Patents Nos. 2,512,667,2,512,600, 2,512,601, 2,512,628 and 2,512,629.

Polyesters, .e. g. those obtainable from terephthalic acid and apolyalkylene glycol.

Copolymers of vinyl chloride with a minor proportion of vinyl acetate.

Acrylonitrile polymers (including co-polymers such as those with vinylchloride or methacrylonitrile) Again, the cellulose acetate yarn may bereplaced by yarn of filaments of another cellulose ester of carboxylicacid e. g. cellulose propionate, cellulose acetate-propionate orcellulose acetatebutyrate, or of a cellulose ether, e. g. ethylcellulose.

Having described our invention, what we claim and desire to secure byLetters Patent is:

1. A process for producing an ornamental knit fabric, which comprisessubjecting to a hot aqueous treatment of warp knitted fabric of whichthe yarns knitted together comprise alternate groups of yarns offilaments having a basis of a material selected from the groupconsisting of a cellulose ester of a carboxylic acid and a celluloseether, and yarns of filaments of oriented synthetic linear polymer.

2. A process for producing an ornamental knit fabric, which comprisessubjecting to a hot aqueous treatment a warp knitted fabric of which theyarns knitted together comprise alternate groups of yarns of celluloseacetate filaments and yarns of filaments of oriented synthetic linearpolymer.

3. A process for producing an ornamental knit fabric, which comprisessubjecting to a hot aqueous treatment a warp knitted fabric of which theyarns knitted together comprise alternate groups of yarns of celluloseacetate filaments and yarns of filaments of oriented nylon 66.

4. A process-for producing an ornamental knit fabric, which comprisessubjecting to a hot aqueous treatment at a temperature of above C. awarp knitted fabric of which the yarns knitted together comprisealternate groups of yarns of cellulose acetate filaments and yarns offilaments of oriented nylon 66.

5. A process according to claim 4, wherein the fabric is such that thebands of fabric derived from one of the kinds of yarn each contain atthe most 60 yarns.

6. A process according to claim 4, wherein the fabric is a plain 2' barwarp knit fabric.

7. A process for producing an ornamental knit fabric, which comprisessubjecting to a hot aqueous treatment at a temperature of above 75 C. alock-knit fabric in which the yarns of each bar consist of alternategroups of yarns of cellulose acetate filaments and yarns of orientednylon filaments, the nylon yarns of the one bar corresponding inposition with the nylon yarns of the other bar, and the groups of yarnsof one kind of each bar each contain from 4 to 18 yarns.

WILLIAM EWA-RT STANLEY.

FRED CARTER BROWN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,130,948 Carothers Sept. 20, 1938 Number Number Name DateMendel et a1 Feb. 14, 1939 Just et a1. Jan. 11, 1944 Foster Oct. 12,1948 Shearer et a1. June 28, 1949 Hinchlifi Oct. 11, 1949 Bloch et a1May 16, 1950 Huey et a1. May 23, 1950 FOREIGN PATENTS Country Date GreatBritain Dec. 24, 1924

